CTSK and arthritic joint disease: Studies are being conducted on natural medicines that directly target specific mechanisms, such as arthritis inflammatory mechanisms (e.g., interleukin [IL-1], tumor necrosis factor [TNF]-α), cartilage mechanisms (e.g., Wnt signaling pathway, cathepsin-K, MMP/ADAMTS, growth hormone inhibitors), subchondral bone destruction, and pain reduction [23].